Does Eccentric-only and Concentric-only Activation Increase Power Output?

Abstract

The aim of study was to evaluate changes in power output and bar velocity in the bench press throw (BPT) following the bench press (BP) exercise as a conditioning activity (CA) with concentric only (CONONLY) and eccentric only (ECCONLY) contractions. Thirty-two (n = 32) healthy strength-trained men participated in this study (age, 28.4 ± 4.5 yr; height, 177 ± 7.6 cm; body mass, 93.5 ± 9.3 kg; BP one-repetition maximum (1RM), 143.6 ± 17.5 kg). The experiment was performed following a randomized crossover design, where each participant performed 2 sets of 2 repetitions using the BP exercise as the CA at 90% 1RM ECCONLY, 90% 1RM CONONLY, 110% 1RM ECCONLY, or 130% 1RM ECCONLY contraction. The BPT was performed to assess changes in peak power (PP), mean power (MP), and peak velocity (PV), mean velocity (MV) before and after CA. The differences between analyzed variables before and after the CA were verified using ANOVA with repeated measures. Statistical significance was set at P < 0.05. There were statistically significant differences between baseline and postactivation value of PP and PV in the BPT (P < 0.05) after the CA with ECCONLY contraction at 110% 1RM and at 130% 1RM as well between baseline and postactivation value of MV in the BPT (P < 0.05) after CA with contraction at 110% 1RM. There were no significant differences between baseline and postactivation values of PP, MP, PV, and MV in the BPT after the CA with CONONLY contraction at 90% 1RM and CA with ECCONLY contraction at 90% 1RM. Partial movement with ECCONLY contraction is effective in short-term power output development, but only when the load used in the CA exceeds 100% 1RM.